The invention relates to a computer system with information processing modules such as shared memories, computer modules, and input/output devices and, more particularly, to a computer system with a configuration monitor in which the connecting condition of the information processing modules with the computer system and the operating condition of them, i.e. the configuration of the computer system, are monitored and supervised.
A computer system is frequently provided with a plurality of input/output devices, for example, as an information processing module. By convention, in this type of computer system, identification numbers respectively are attached to the input/output devices such as card readers, line printers, magnetic tape memories, and magnetic disks. These input/output devices are sometimes disconnected or reconnected independently from the computer system during its operation for the purpose of maintenance, inspection or repair. In such a case, it is necessary to inform an operating system (OS) of the computer system of the connection or disconnection of an identification-numbered module. In the case of the connection or disconnection, the input/output (I/O) devices including the operating ones are often renumbered as to their identification numbers. The renumbering operation is manually carried out by using a switch provided on the I/O device. Then, the operator informs the OS of the identification numbers renumbered. That is, the operator communicates with the OS through a console typewriter for reporting the new identification numbers or the configuration of the I/O devices to the OS. However, when the operator makes an error in the console operation, the computer system erroneously operates or halts. Further, in the case where the computer system includes a plurality of central processing units (CPU), and these CPUs are individually connected or disconnected to and from the computer system, the operator must devote great care to the console operation, because an operation error by the operator possibly brings about serious deterioration of the reliability of the computer system.